The search for mysterious "fast radio bursts" – very brief but intense pulses of radio waves from outer space – is heating up. Nobody knows what causes these powerful bursts, but some have even speculated that the signals ...

Researchers working with Wojciech Hajdas at the Paul Scherrer Institute PSI have developed a detector called POLAR. This instrument is expected to search out and investigate so-called gamma ray bursts coming from the depths ...

A new way to use the most powerful explosions in the Universe to calibrate its expansion has been developed by a team of researchers (Sergey Postnikov, Xavier Hernandez from Institute of Astronomy , UNAM, and Michal Ostrowski ...

Twenty-five years ago this week, NASA launched the Compton Gamma Ray Observatory, an astronomical satellite that transformed our knowledge of the high-energy sky. Over its nine-year lifetime, Compton produced the first-ever ...

Last February a team of astronomers reported detecting an afterglow from a mysterious event called a fast radio burst, which would pinpoint the precise position of the burst's origin, a longstanding goal in studies of these ...

Astronomers are getting ever closer to understanding the origin of mysterious "fast radio bursts" – very brief but intense pulses of radio waves from outer space – after a series of recent contradictory findings. While ...

(Phys.org)—Sometimes when a star collapses into a supernova, it releases an intense, narrow beam of gamma rays. Gamma-ray bursts often last just a few seconds, but during that time they can release as much energy as the ...

On September 14, 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves from the merger of two black holes 29 and 36 times the mass of the Sun. Such an event is expected to be dark, ...

Last week's announcement that Gravitational Waves (GW) have been detected for the first time—as a result of the merger of two black holes—is huge news. But now a Gamma Ray Burst (GRB) originating from the same place, ...

The sources of the high-energy cosmic neutrinos that are detected by the IceCube Neutrino Observatory buried in the Antarctic ice may be hidden from observations of high-energy gamma rays, new research reveals. These high-energy ...

Gamma-ray burst

Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions in distant galaxies. They are the most luminous electromagnetic events occurring in the universe. Bursts can last from milliseconds to nearly an hour, although a typical burst lasts a few seconds. The initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio).

Most observed GRBs are believed to be a narrow beam of intense radiation released during a supernova event, as a rapidly rotating, high-mass star collapses to form a black hole. A subclass of GRBs (the "short" bursts) appear to originate from a different process, possibly the merger of binary neutron stars.

The sources of most GRBs are billions of light years away from Earth, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the Sun will in its entire 10 billion year lifetime) and extremely rare (a few per galaxy per million years). All observed GRBs have originated from outside the Milky Way galaxy, although a related class of phenomena, soft gamma repeater flares, are associated with magnetars within the Milky Way. It has been hypothesized that a gamma-ray burst in the Milky Way could cause a mass extinction on Earth.

GRBs were first detected in 1967 by the Vela satellites, a series of satellites designed to detect covert nuclear weapons tests. Hundreds of theoretical models were proposed to explain these bursts in the years following their discovery, such as collisions between comets and neutron stars. Little information was available to verify these models until the 1997 detection of the first X-ray and optical afterglows and direct measurement of their redshifts using optical spectroscopy. These discoveries, and subsequent studies of the galaxies and supernovae associated with the bursts, clarified the distance and luminosity of GRBs, definitively placing them in distant galaxies and connecting long GRBs with the deaths of massive stars.